I recreated from blueprint new geometry, this one is watertight and I’m finally able to import it as multiple faces.
I also created some more scenarios.
-Trapezlip(Similar to one from the document I posted above, but slightly moved towards the glass.)
-Dashspoiler(Small dash which makes rear end longer)
-Windowdash(Just like above but on the glass behind roof)
-Windowdash&lip(Just a combination of two from above)
-Bigspoiler(Something like Toyota Supra)
The plots are configured as follows.
I’ll tried to configure Cd properly as positive values, but when I paired it with forces plots it makes sense for me even in negative so for sake of comparision i left it as it is.
-Reference length 5m
-Reference Area 0.5m^2
-Drag direction on positive Y, velocity is (-35)
-Lift direction on positive Z, which should be upwards
Selected faces excludes drag modifiers(dash is only modifier included). Since in theory spoilers shouldn’t even be hit by main flow, differences were marginal. However bigspoiler shows decreased uplift when included, but its high and is in path of main flow.
Pressure planes looks as follows.
Data from plots looks as follows:
It looks like stock spoiler is some kind of sweet spot between creating a stagnant pocket which slows down air on rear end which as result reduces uplift and creating lesser wake than other cases because of space underneath.
Various additions in form of lips or slightly facing upwards dash, are creating bigger pocket which reduces uplift even further at cost of bigger wake region, although slightly moved lip leaves a clear path on rear edge, which maybe after some adjustment will give similar results to stock spoiler.
I think wall greatly stabilizes rear end in cornering, maybe I made it too big.
Window dash and bigspoiler are in my opinion useless (values in parentheses are after including spoiler faces into account).
I don’t know how to read forces moment, is it in N*m?
What do you think, does it makes sense?
Maybe there is something on your mind which I should include in those tests?
I’m out of ideas for now .